Various services in advanced networks, wireless or wireline, rely on packet-based protocols for delivery of data and signaling. Such advanced networks generally exploit a group of application servers that generate at least part of the data and signaling that provide content and enable specific functionality associated with a service, such as voice over internet-protocol (VoIP), IP multimedia content delivery, caller identification (ID) in IP television, etc. In certain architectures, the group of servers is deployed in an application layer, which is functionally coupled to a control layer that typically includes several session control components that enable a service session (e.g., a VoIP call, a data call, delivery of a pay-per-view movie . . . ). An example of such architecture is 3GPP IP Multimedia System (IMS) core network. In 3GPP IMS core network, a session control component is embodied in a control session control function (CSCF) node, which can be a Serving CSCF (S-CSCF) node, Interrogating CSCF (I-CSCF) node, a Proxy-CSCF (P-CSCF) or a transit function node. In addition, in 3GPP Long Term Evolution (LTE) networks, a Mobility Management Entity (MME) can embody a session control component.
To enable, in part, access of a subscriber device (mobile device, customer premises equipment, etc.) to network resources associated with a service, application servers, session control components, or other network nodes, generally acquire data from a centralized network repository, which operates as a master database. In 3GPP architecture for next generation networks (NGN), Home Subscriber Server (HSS) can embody the centralized network repository master user database. A HSS can contain subscription-related information (subscriber profiles, subscriber credentials, etc.). In addition, the HSS can perform authentication and authorization of a subscriber device, and can provide information about the subscriber's location and IP information. HSS also can provide services to call processing nodes, such as Call Session Control Functions (CSCF), or application feature servers in 3GPP IMS core network or 3GPP LTE networks.
Various protocol interfaces, such as Diameter protocol interfaces, enable access to data in HSS from a client. Such access to data is commonly accomplished via protocol messages, which generally are not equally critical or urgent. As an example, some Diameter queries from I-CSCF or S-CSCF are directed to registration or re-registration of subscriber devices (UEs, CPEs, etc.). While initial registration is critical for a subscriber device to receive subscribed services, re-registrations are not equally important and may remain without a response from HSS for a few minutes since a subscriber device typically requests re-registration several minutes (for example, 10 minutes) prior to registration expiration. As another example, some message requests from I-CSCF to HSS are directed to end-to-end call processing whereas other requests originated in I-CSCF are intended to an application that issues message waiting indications.
Additionally, in complex, large (e.g., several thousand nodes) next generation network deployments based on 3GPP IMS core network elements or 3GPP LTE network elements, performance of HSS can be subjected to various heavy-load or overload conditions. When a HSS load is heavy, it is desirable for HSS to favor more critical application requests rather than non-critical ones. Moreover, when a HSS is in an overload condition, the HSS can reject or silently drop some request messages; it is desirable for the HSS to reject or drop less critical requests first. Yet, in conventional network systems, it is common for the same client to employ the same type of Diameter message for different service applications directed to access data for different operation purposes. Accordingly, management of message requests at HSS typically fails to be efficient.